VBox 4.1.14 w guest Win7 crashes after several days, is not working anymore

my VB installation isnt working anymore. the 4.1.14 inst. has crashed some days before, rm of all VM dir and files, pkgrm and installation of the actual version doesnt work.
The main window appears, after several sec VM is coredumping.

The machine was started with root-rights, actual there is no VM attached or created

my VB installation isnt working anymore. the 4.1.14 inst. has crashed some days before, rm of all VB dir and files, pkgrm and installation of the actual version doesnt work.
The main window appears, after several sec VM is coredumping.

The machine was started with root-rights, actual there is no VM attached or created

I can only answer the question regarding why does VBox check the permissions of /opt. The reason is that VirtualBox is system software which has special privileges. If the permissions of the directory where VirtualBox is stored would be wrong then an unprivileged user could replace some binaries and could do bad this. Same problem if a user could write to parent directories (e.g. /opt). Some checks are perhaps a bit pedantic but better safe than sorry.